Envelope



FIG. 1 is a perspective view of the envelope embodying the design of the present invention;

FIG. 2 is a front elevational view thereof, it being understood that the decorative element on the upper right corner is a surface design feature;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom view thereof. 

The ornamental design for an envelope, as shown and described. 